Twisted nematic liquid crystal displays are widely used in the display field due to their good time response, good contrast and good transmittance characteristics. With the continuous development of display technology, higher and higher demand for resolution of liquid crystal display panel is proposed. Cost of integrated circuit (IC) increases, and yield rate of pressing welding decreases, with the improvement of resolution. In order to reduce IC cost, some panel designs adopt double gate line design. Double gate line design refers to provide two gate lines for each row of pixels, and two adjacent columns of pixels share one data line. Because the cost of the data line driver IC is lower than that of the gate line driver IC, the overall IC cost of the liquid crystal display device is reduced. However, the double gate line design will reduce aperture ratio of a liquid crystal display panel.